Digital 3D fabrication is utilized to replicate complex structures that are difficult to make with bulk machining. Existing 3D fabrication techniques such as inkjet/extrusion and “two-photon lithography” (TPL) are utilized to produce tiny structures with features on a micron (μm) or nanometer scale, but have drawbacks in terms of resolution and z-height limits. The resolution of 3D inkjet or extrusion printer is acutely affected by the composition of solution inks, and often the requirements for good printing are in conflict with the desired mechanical properties in the printed structures. For example, the solid loading in nanoparticle inks is kept low to avoid particle agglomeration and clogging of ejectors, but in terms of structural integrity, higher loading is preferable to minimize shrinkage and facilitate solidification. The colloidal suspension for inkjet and extrusion are already at picoliter volume in order to reach 40 μm resolution (˜600 dpi in Objet 3D printer). For further improvement, the droplet volume has been successfully reduced by applying an electric field, but the reduced volume that enables higher the resolution will trade off with speed in the process. Major breakthroughs in the write speed for TPL were announced in 2012 by the Vienna University of Technology on a research TPL system, and in 2013 by Nanoscribe GmbH in a commercial TPL system. However, large vertical distance is still problematic for TPL, because the focal length of TPL optical system is limited to few hundred microns maximum.
What is needed is a process for fabricating 3D structures that avoids the resolution and z-height limit restrictions of conventional modeling methods.